Many parents have observed inadequate sleep in children is associated with daytime behavioral problems and poor academic functioning. A fact less well-recognized by clinicians and the general public is that sleep-related breathing disorders, which occur in two to 10% of children depending on how they are defined, can have a significant impact even among children who have normal sleeping hours.
One of the most severe nocturnal breathing diseases, obstructive sleep apnea (OSA), includes partial or complete breathing blockage recurrently during sleep, resulting in intermittent low level of oxygen in blood and probable sleep disruption. The frontal and hippocampal regions of the brain, which are implicated in the regulation of behavior and memory, respectively, appear to be most vulnerable to OSA, but the evidence is indirect.
Proton magnetic resonance spectroscopy (MRS), a non-invasive neuroimaging technique are used to detect chemical metabolites linked to neural dysfunction, to shed more direct light on the neural functioning of children with OSA.
The Study Findings
In comparison, children with OSA have significantly lower on tests of overall intelligence and some aspects of higher-level thinking called “executive functions,” but the groups did not vary on tests of sustained attention, or motor skills. Tests of memory did not give significant differences between the groups, but the effect sizes were large enough to suggest that significant effects might have been found in a larger sample. MRS specified that those with OSA had abnormal metabolites in the left hippocampus and right frontal cortex.
Implications for Brain Development and Clinical Practice
These parallel findings of shortage on measures of behavioral and brain functioning in children with OSA are sobering, and gives support to concerns that OSA, if it is not treated, it may cause substantial long-term adverse effects. The developing brain does not just unfold in a predestined genetic process. But, it builds upon itself at every level, with development by the interaction of genes with the immediate cellular surroundings. That surrounding is estimated by the child’s life experiences (e.g., reactions to OSA-related behavioral disturbances) and physiological functioning (e.g., OSA-related oxygen deprivation or sleep disruption). Due to this, untreated childhood OSA may have a specifically marked long-term impact.
Pediatricians and other health-care professionals must increase their consistency in screening for symptoms of OSA. Sleep is seldom addressed in most pediatric clinics, even though clinical screening tools are easy to use for testing. This lack of clinical attention runs difficult to current evidence from sleep medicine and developmental neuroscience, which suggests that early disorder diagnosis and treatment should be a high priority.
Limitations of the Study
The studies in current research withstand replication, because they are consistent with adult studies that have shown similar abnormalities using MRS, and with current theories of the mechanisms behind the daytime deficits observed in individuals with OSA. Yet, more research is needed to verify and build on these theories. MRS gives indirect indices of neural dysfunction (not necessarily neuron death), and it is not clear whether those indices will become normal with effective OSA treatment or what long-term effects might continue. Similarly, although the current theories gave tantalizing suggestions of developmental effects, few children below the age 10 were able to tolerate the sedative-free MRS procedure, as they should be lying still during the scan. As a result, the high-risk period for OSA in preschool and early grade school remains are still not mainly considered by this study. By targeting on relatively severe cases, the study also is not considered for milder forms of sleep-disordered breathing, which are more prevalent than severe forms and which have been found to rise in the risk for behavioral problems. At last, these theories will need to be replicated in completely community-based samples. Children who are referred for clinical estimation in a sleep clinic are likely to have other problems that brought them to their concern of referring professionals in the first place